This study proposes to use a simple, noninvasive method that assesses intestinal permeability to two sugar substances (lactolose and mannitol) to (1) demonstrate a difference in intestinal function between HIV- infected and HIV-uninfected children, and to (2) evaluate the effect of growth hormone on the intestinal barrier function in HIV-infected children with growth failure. Underlying this proposal are the hypothesis that HIV- infected children with growth failure have decreased intestinal barrier function, and that growth hormone may improve mucosal integrity in these children. Results from this study will improve our understanding of (AIDS) in children, add to our present knowledge on the effects of growth hormone on gastrointestinal function, and confirm the value of the permeability test in the evaluation of gastrointestinal function.